This invention relates to a load cell used primarily in scales, and seeks to enhance load cell durability.
A load cell of the aforementioned type comprises a load-sensitive element which develops strain the magnitude of which corresponds to an applied load, and a strain gauge cemented to the load-sensitive element to detect the amount of strain electrically. It is necessary to protect the strain gauge against moisture and humidity in order to enhance its durability and maintain good operating performance. Conventional practice has been to either coat the strain gauge with a moistureproof material such as silicone rubber, or seal the strain gauge by means of a metal foil. However, the former technique does not provide sufficient protection against moisture in the moist and humid environments where load cells commonly find use in scales. While the latter expedient affords excellent protection against moisture, the metal foil has little stretchability and therefore hinders the deformation of the load-sensitive element, thereby having an adverse effect upon the load - strain characteristic of the load-sensitive element.